Wireless Wheel kit rotary switch floating voltage

OTHER DEVICES
1

On the new wireless wheel kit, what is the value transmitted for the rotary switch if the RS+ isn’t connected to any of the input pads? Does it just float or is there a pull-up/down somewhere that will kick it to 0, 1, 8, or 9? If there is RS+ applied to (for example) R2-pin3 and then the power is pulled from pin3 but not applied anywhere else, would that trigger the board sending a CAN update or would a new message only come if/when the RS+ signal is seen on a different pin? If it doesn’t send anything for the rotary value CAN msg, would it at least send an update that the analog voltage msg has changed (and what would it change to, or would it be left to float?)

I’m trying to suss out the possibility of using one of the rotary inputs to add 7-8 additional switch inputs (albeit with the caveat that only 1 could be pressed at a time, but I already have a plan for that)

2

Hi!

please check my answers below:

On the new wireless wheel kit, what is the value transmitted for the rotary switch if the RS+ isn’t connected to any of the input pads?

Value 0(voltage 555 mV) is trasmitted(if Rx: offset in LC is set to -1).

Does it just float or is there a pull-up/down somewhere that will kick it to 0, 1, 8, or 9?
Each rotary switch input is pulled down, so they not float.

If there is RS+ applied to (for example) R2-pin3 and then the power is pulled from pin3 but not applied anywhere else, would that trigger the board sending a CAN update or would a new message only come if/when the RS+ signal is seen on a different pin? If it doesn’t send anything for the rotary value CAN msg, would it at least send an update that the analog voltage msg has changed (and what would it change to, or would it be left to float?)

The wireless steering wheel kit panel will wake up to send an update only when the RS+ voltage appears on another pin. So, if you apply RS+ voltage, for example, RS+ → R1.pin2, you will get in the LC R1 = 1 (when R1 offset = -1), A1 = 1110. When the RS+ voltage disappears from pin R1.pin2, the value R1 = 1, A1 = 1110 will still be sent over CAN. For the state to be updated, RS+ voltage must be applied to another pin of R1. Pins R1-R4 are designed to work with rotary switches, where only one active position of the rotary switch connects RS+ with Rx.pinx (where x is the index of the rotary switch and the pin number).

The analog voltage visible in the LC is not the actual voltage on the R1-R4 pins. The state of the rotary switches is a digital value, later converted to an analog voltage to maintain compatibility with the CAN SwitchBoard V3.

I’m trying to suss out the possibility of using one of the rotary inputs to add 7-8 additional switch inputs (albeit with the caveat that only 1 could be pressed at a time, but I already have a plan for that)

These inputs were not intended for such use. To detect the release of such a button and update the value, you would have to choose one of the values (0-7) (when offset -1) as the neutral position, for example, 0(Rx.pin1), and by releasing any of the other buttons (let’s say from 1 to 7), short RS+ to Rx.pin1. In this situation, I imagine it could work as you intended.

Maciej

3

Thank you, that was sort of what I was expecting; using one pin as a “neutral” state was kind of my plan for that situation, which would be easy enough using two circuit buttons with the neutral pin run in series on the NC circuit of each. But my concern there is the problem the buttons not being designed for break-before-make so the could be a fraction of a second where both the neutral pin and the button pin are high as it is pressed or released. You say the logic on the rotaries is natively digital, does it have any filter logic for this or what would happen if two buttons were pressed at once?

I know I’m not using this as intended, I’m just really trying to simplify operation of the controls for the driver by laying out dedicated buttons for some operations rather than relying on multifunction states that require compound actions from the driver. I appreciate all the support you guys give for questions like these, being able to get low-level engineering questions answered and the level of control and freedom you give to the user is what makes you guys the best.

4

Well, high level of signal on two RS pins at the same time will not be handled correctly at this moment, since it is not possible to acheive with rotary switch.

If there is a high state on pin 0 (our neutral) and you press a button (for example on pin 1), for a fraction of a second both pin 0 and pin 1 will be in a high state—you will see the correct value in the Light Client and the rotary switch value will change from 0 to 1. However, when you release the button and the value is not updated back to 0, the high state must first disappear from pin 1 and then appear on pin 0. If both pins are in a high state, the value 0 will not be updated. For it to be updated in this situation, the steering wheel panel would need to be woken up, which would require pressing any other button or changing the state on the rotary switch pins.

5

Gotcha, thank you. I’m trying to reorganize myself so I can use the board as designed but this will at least be a fun design challenge to think about over my morning coffees.

6

Out of curiosity, will there eventually be a way to buy additional transmitters without purchasing the kit that includes the receiver? The manual references having multiple wheels for endurance events (which is my application) but I don’t know how to purchase anything other than the full kit.

7

There will be the possibility to purchase the transmitter and receiver separately in the near future.